Field of the Invention
The invention relates to an antenna module and, more specifically, to an antenna module of a portable electronic device.
Description of the Related Art
Multiple antenna systems, such as a Pattern Switchable or Beam Steering Antenna system and a Multi-input Multi-output Antenna (MIMO) system, are developed for the demand for better signal quality, and higher reliability and the transmission speed of wireless signals. For example, the MIMO technology is already applied in products successfully, such as in a notebook, a handheld communication device and a wireless access point.
To solve the problem of multiple-path fading of the antenna, the MIMO antenna system is widely used. However, the wireless electronic devices on the market are designed lighter, smaller, and thinner, which results less space for placing antennas and the isolation between antennas is thus reduced. As a result, the fundamental frequency signal is not easily processed, the transmission speed is slow, and the interference between the antennas makes the gain decreased.